'72 bed tweaked?

[FORDification]

I'd say 90% of the time when the bed appears crooked like that, it's one of the suspension's springs. Either they're fatigued and sagging, or (in the case of leaf springs) sometimes broken.

Since your front springs already have those twist-in spacers, I'd say that they're the culprit. I'd be willing to bet that if you were to replace those front springs, your bed will once again sit level.

[averagef250]

Owning a good number of bumps, I've seen a few with crooked bed syndrome. One was really beat suspension/possibly bent frame. The other two were both victims of a poorly installed replacement bedside at some point. I have one of these beds in my driveway right now. If I measure from the top of the bed down to the bed floor at the tailgate there's a 3/4" difference from side to side. Of the two beds I've seen like this the reason they were crooked was the same- The replacement bedside was made wrong. At the bottom of the tailgate jamb there's a flange broken at 90 degrees from the bedside rear pillar that's spotwelded to the rear bed crossmember. This little flange was simply broke in the wrong place and the body shop that installed the bedside didn't catch it before they welded the whole thing together.

Look for any signs the bedside's been replaced like the presence of MIG welds, brazing or rivets. The factory used only spot welds. Measure from bedside top to the floor at the front and rear and compare the sides.

If all that checks out, put the truck up on jack stands off the frame completely unloading the suspension. Try to do it on flat concrete.

The 4x4 frames are pretty stout. A truck is usually totalled, I mean really non-rebuildably totalled by the point the frame tweaks.